fix android build

after
    commit 37f9fdc1
    replace rtl_allocateMemory with std::malloc

just add cstdlib as in include to the compatibility header, so that
std::malloc/etc is visible

Change-Id: I3f0569434c41f5427a037a3c8d0ff75389169241

include/android/compatibility.hxx

@@ -23,6 +23,7 @@
 #include <stdlib.h>
 #include <string>
 #include <sstream>
+#include <cstdlib>
 
 namespace std
 {